Bruce Elly/The OregonianThe federal Cash for Clunkers program has stimulated huge sales locally and nationally. Bob Wentworth of Wentworth Chevrolet says the Southeast Grand Avenue dealership already has 31 clunkers stacked up behind East Side Auto Body. The vehicles are slated to be junked out in Vancouver.

Oregon auto dealers love the "cash for clunkers" rebate program, which is goosing stalled sales. They hope the U.S. Senate will agree to add $2 billion next week, extending the rare boom.

Yet in their back shops, dealers struggle with a 136-page rule book, a balky government Web site and refund delays that could hurt their cash flow.

"This is an outstanding program, but I'm just nervous," said Chris Meier, general manager of the Herzog-Meier dealership in Beaverton. "I'm taking a very careful look at doing any further deals until I have some good feeling that I'm going to see some of my pending claims accepted."

Under the clunkers initiative, a dealer discounts a new vehicle by as much as $4,500 when a customer trades in an old car for one that gets significantly higher gas mileage. The dealer then applies to the government for approval and a refund.

On Friday, the U.S. House of Representatives voted 316-109 to extend the program, which may have exhausted its $1 billion budget during the first week. House members acted within hours of learning from Transportation Secretary Ray LaHood that the program was running out of money.

President Barack Obama praised the House's quick work, saying the program had "succeeded well beyond our expectations and all expectations, and we're already seeing a dramatic increase in showroom traffic at local car dealers."

Sen. Jeff Bingaman, D-N.M., said he was concerned with the way the House had paid for the extension, shifting $2 billion from a renewable energy loan program. He said that would "rob from the loan guarantees we provided through the recovery package that, in the long-term, will shift our country to homegrown, renewable energy while creating good green-collar jobs."

Still, car buyers across the country are flocking to dealerships. Lithia Motors, the Medford-based company with 88 new-car outlets nationwide, reports customers lining up at its stores late into evenings, anxious for deals.

In Bloomington, Minn., on Friday, Dennis and Marcia Strom hurried to Walser Toyota when they heard the rebate might not last.

"I might have waited until the truck died," Dennis Strom said of his 14-year-old Dodge Dakota. "It's a good vehicle that suits our needs. But it's not worth $3,500."

Buyers and dealers praise the clunkers program for stimulating the economy by giving money directly to consumers, unlike most other stimulus programs. The cash moves quickly downstream, multiplying its economic impact, they say.

"This is the first stimulus program they came up with that I think works," said Victor Winkler, president of Metro Metals Northwest Inc.. The Portland company's subsidiary, Pacific Coast Shredding, is crunching hundreds of the clunkers at the Port of Vancouver and sending the scrap to Asia.

The White House says deals completed this weekend will be honored. But no one knows how many jalopies have been traded in locally or nationally since the program began July 24, set initially to expire Nov. 1.

Sen. Debbie Stabenow, D-Mich., said about 40,000 vehicle sales had been completed through the program. Dealers estimated they were trying to complete transactions on an additional 200,000 vehicles nationally, leaving the funding in doubt. If all cars in the program qualified for the full $4,500 rebate, for example, about 222,000 transactions would consume the initial $1 billion.

The hastily assembled system appears backward to Meier, whose dealership has completed about 20 of the sales.

"They have no true clarity as to how much obligation has been established out there by the dealerships in the United States," Meier said. "We've got to get our deals in as quickly as we possibly can in the fear that by the time we get some of our last ones in, the money's gone."

The government should have enabled dealers to go on-line and deduct up to $4,500 from the total fund, he said, filing documentation within 30 days. Instead, dealers complete the transaction, provide the rebate and apply for the refund, using a clunky Web site that repeatedly crashes.

Some dealers said on-line processing took upward of an hour for each transaction, caused repeated rejections and consumed many hours submitting and resubmitting data. Federal officials said they have increased the capacity of the submission system and added staff to work hot lines and process voucher applications.

Ron Tonkin, president and chief executive of the Portland-based Ron Tonkin Family of Dealerships, finds the 136-page rule book "mind boggling," along with the $15,000 fine for dealers who do something wrong. But Tonkin said the program far exceeded his expectations, producing 40 sales at his company's Kia outlet during the first four days.

Tonkin, whose company has 18 stores, plans to keep doing the deals.

"Until the program is officially negated, then it's my feeling that the program still exists," Tonkin said. "So we're going to do business under the program until they say there is no more program."

Some Oregon dealers have completed more than 70 clunker transactions, often adding their own rebates, said Greg Remensperger, executive vice president of the Oregon Auto Dealers Association.

"There's a lot of confusion out there as to what qualifies and what doesn't," Remensperger said. "There is a huge pent-up demand to buy vehicles in this down economy."

Bob Wentworth, a partner at Wentworth Chevrolet and Subaru, had thought that people who owned qualifying cars might not be able to afford new vehicles.

"But that hasn't been a factor at all," he said. "The issue now is that inventories are getting low."